In many technical fields it is necessary to know a fluid flow, thus in particular a gas flow or liquid flow, with respect to its volume flow rate (volume per time) or with respect to its mass flow rate (mass per time) so as to be able, for example for proper operation of a device working with such a fluid flow, to control or regulate the fluid flow with respect to its volume flow rate or its mass flow rate, or to be able to set parameters of the device which depend on the volume and/or mass flow rate of the fluid flow.
For example, in case of an internal combustion engine equipped with exhaust gas recirculation it is required to know the recirculated exhaust gas quantity, for example to be able to monitor, thus control and/or regulate, an exhaust gas recirculation valve controlling the recirculation quantity. In this case, the fluid flow to be measured is the recirculated exhaust gas flow rate or, respectively, the recirculated exhaust gas flow. The same applies also for example to a fresh air supply of the internal combustion engine.
The present invention is concerned with the problem to provide a way for measuring the fluid flow rate, in particular the exhaust gas flow rate, which is characterized by a fast acquisition of measured values and/or by a compact design.
This problem is solved according to the invention by the subject matters of the independent claims. Advantageous embodiments are subject matter of the dependent claims.